formatting phone number in c++ - c++

Question

Please assist, I am trying to format a phone number like [phone]. I have the following code which works but I would like to write much shorter.
int main(){
string phone_number;
cin >> phone_number;
cout<<"(";
for(int i = 0; i < 3; i++) {
cout << phone_number[i];
}
cout << ")";
for(int i = 3; i < 6; i++) {
cout << phone_number[i];
}
cout << "-";
for(int i = 6; i < 10; i++) {
cout << phone_number[i];
}
cout<<endl;
return 0;
}
please assist

Answer 1

Another possibility:
cout << "(" << phone_number.substr(0,3) << ")"
<< phone_number.substr(3,3) << "-" << phone_number.substr(6,4) << endl;

Answer 2

Use string::insert. But since you are taking a string as input, why wouldn't you give the input in format you need. Any how, this is how it can be done with out any loops if you wish to modify the string. In case you don't wish to change the original string then store the modified to a different temporary variable.
string phone_number = "123456789";
phone_number = phone_number.insert( 0, "(" ); // Original string is modified
// Rest can be achieved in similar fashion
cout << phone_number << endl;

Answer 3

for (int i=0; i<10; ++i)
{
if (i == 0) std::cout << '(';
else if (i == 3) std::cout << ')';
else if (i == 6) std::cout << '-';
std::cout << phone_number[i];
}

Answer 4

Probably wouldn't be good to change your data just to format.
string str(phn);
// Format Phone# 1: void function
printf("(%s)%s-%s",
str.substr(0,3).c_str(),
str.substr(3,3).c_str(),
str.substr(6, 4).c_str());
// Format Phone# 2: returns std::string&
stringstream p;
p << "(" << str.substr(0, 3) << ")"
<< str.substr(3, 3) << "-"
<< str.substr(6, 4);
return p.str();

Answer 5

Ignoring the question as to why you want to write this "shorter" ...
printf("(%c%c%c)%c%c%c-%c%c%c%c\n", phone_number[0], phone_number[1], phone_number[2],
phone_number[3], phone_number[4], phone_number[5],
phone_number[6], phone_number[7], phone_number[8],
phone_number[9]);
That being said - your code (nor this) checks to see if there's actually 10 numbers present, or if they're numbers at all. That above all is more important than wanting it "shorter".

Answer 6

Your code is too short, not too long. Any input from the user must always be checked for validity. For instance, what if the used already entered the punctuation, so that phone_number contains "[phone]"? Then your code would output "((11)-)11-1-11" (I think). This is not what you want. At the very least, you must throw out all non-digit characters.

Answer 7

#include <iostream>
using namespace std;
int main(){
string phone_number;
cin >> phone_number;
cout<<"(";
for(int i = 0; i < 3; i++) {
cout << phone_number[i];
}
cout << ")";
for(int i = 3; i < 6; i++) {
cout << phone_number[i];
}
cout << "-";
for(int i = 6; i < 10; i++) {
cout << phone_number[i];
}
cout<<endl;
return 0;
}